heating element



8 v "TCROSS'REFERE|\ICE March 13, 1945. B. F. WHEELER 2,371,275

2 HEATING ELEMENT I 7 Filed Dec; 26, 1942 Inventor fl yrklilm z Attorney5 y I Byrhl 15''. Wheeler, Balston Spa, N. Y.', assignor or".

,, -four.te'en per cent to Joseph Vigneault and I twenty-six per centto'Martinien Lacombe,both *1 "of MontreaLQuebec, Canada ApplicationDecember 26, 1942, Serial No 470,150? 2 a ""i'fomhnj -i ,(crz af-cc IThe present invention relates to heating'ele ments and, moreparticularly, to electric elements.

of'a cast lithic-like nature adapted to heat water. Electric heatingelements operating in water have been known for a long time and arebased on a number or operating principles. In most cases, 1 however, theheating effect isobtained by forcing an electric current through aresistance,whether of a metallic-wire type, the carbonaceous type orthewateritself. H Saidheating elements, however',"possess draws backsattributable to. the breaking down, corrosion erenc characters representcorresponding partsthroughout, the numeral I indicates the casing onepiece to include inlet opening H, outlet opening l2 and a threadedaperture l3 at the bottom adapted to receive a plug 14. Said plugisintencled to support the element l5, fitting snugly within-Consequently, the main object of the invention Y may be stated to residein a water-heating element of very high efficiency. 7

Another important object of the invention con-' 'cerns a composition forwater-immersed electric heaters, which composition is highly refractoryto 4 limits of electrical standards and at relatively low cost. I

Other objects and advantages of the invention will become apparent asthe description progresses.

As anexample of the kind of heating elements rendered possible by theinvention, a form of such an element is shown in the anne red drawing,wherein the element is used as a practical application to a waterheater.

Inthe drawin Figure 1 is a perspective view of the water heater,

Figure 2 is a vertical section through the heater,

Figure 3 is a vertical section through the element,

Figure 4 is a section taken on line 4-4 of Figure 1, and

Figure 5 is a section taken on the line 55 of Figure 2.

terminal bolts l1.-' i

the well I6 formed inthe-plug'by means of the As shown to advantage inFigure3 the plug is provided with a pair of spaced apertures ll! of "abore 20 axially formed in the center of said element IS. The strips 28are bentright-angularly' at the bottom and perforated'to receive thebolts- I1 and to contact the heads thereof to form a good electricconnection. In order to facilitate circulation, apertures 23 ai'eformedtransversely in the body of the elementthrough the inner bore. 4

So constructed, the element is readily attachable to the plug by thesimpleexpedient of inserting the bolts through the bushings l9, placinginsulating washers 2] over the bolts protruding outside the plug andsecuring said bolts by the nuts 22. The element mounted in the plug maythen be attached to a variety of heaters, such as the one shown.

The terminal arrangement shown is at one end only of the elementalthough, obviously, connections could be disposed as easily at bothends for special purposes.

As stated previously, the feature of the invention resides in thelithic-like resistance composition used to form the body of the heatingelement. Said composition is constituted of native mineral ores, asiliceous insulator and a Portland cement binder.- It is adapted to becast, in the cold state and in the form of an aqueous paste;

Referring to said drawing, wherein similar refto the hardening processis the natural setting of the cement, whereby a homogeneous, lithic,indestructible body is obtained.

More specifically, the current-conducting portion of the composition isrepresented by copper andiron ores, traces of silver ore, all as sulphursalts, and traces of gold in the free state.

Said ores may be a mixture of iron pyrite (FeSz) and chalcocite (CuzS)or, in some cases,

the combined iron-and-copper ore: chalcopyrite (CuFeSa); Generallyspeaking, the traces of gold and silver exist naturally in the oresfound in The purpose of the sand is to disseminate, more or less, theparticles of the current-conducting ore particles and, accordingly, toincrease the resistance of the element to current conduction. 1a

"mersion heating element constituted of Portland The percentage of thesiliceous matter may be comprised between a minimum of 30% and a maximumof 60%.

of the theoretical B. t. u.s available in a given electrical unit ofelectric power are obtained as usable heat from said heating units.

From the foregoing, it will be evident that the present invention is amost useful advance in the art of electric immersion heaters.

It is to be understood that the form of my invention herein shown anddescribed is to be taken as a preferred example of the "same, and thatvarious changes as to the sh p size and arrangement of parts may beresorted to without departing from the spirit of the invention or thescope of the subioined claims.

Having thus described my invention, I claim: 1. As an article ofmanufacture, a lithic imcement having disseminatedtherein grains of cop-All the constituents of the composition are suit-i. r-

ably ground, unrefined, properly mixed and made into a paste with water.The element is then cast in the shape desired, the conducting stripsplaced in position, terminal bolts inserted, etc.,

and the whole allowed to set normally,

As soon as the setting is complete, the element is ready for use,although its exact electrical characteristics will not be fixed atfirst, but will slightly change after the first few hours of use andwill gradually improve with age. i

It has been found that elements constructed according to the inventionare remarkably stable to corrosion and other destructive effects causedby ordinary waters; furthermore, the homogeneous structure renders saidelements strong, re-

sistant to breakage and quite free from the cal careous accumulationscommon to heaters cp- 3 crating constantly in water. a I I As might beexpected, the efficiency of such a water-immersed element is high, muchhigher than other elements using metallic heating resistances. Impartialtests, conducted with various heating units made according to theinvention, have shown conclusively that: up to 98% Percent Portlandcement 40 to 80 Siliceous matter 30 to Iron and copper ores (assulphides) '2 to l5 Gold p Traces Silver Traces 4. An electric immersionheater having electrodes constituted of Portland cement, siliceousmatter and grains of iron, copper and silver sul-, phide oresdisseminated in the mass of, cement and siliceous matter, and opposedcurrent-conducting means embedded in said electrodes. i

